Ulster are facing the loss of another key player for their April 28 Heineken Cup semi-final showdown against Edinburgh in Dublin.

Scrum-half Paul Marshall is a major doubt with an arm injury suffered after scoring a 35th minute try in Saturday night's surprise 26-21 Pro12 League defeat by Connacht in Galway.

Suspended tight-head John Afoa is sidelined until May 7 so Ulster can ill-afford the loss of any more players with the crucial Heineken clash less than two weeks away.

Marshall (26) was taken to hospital for X-Rays and coach Brian McLaughlin said: “We still aren’t sure how bad it is at this stage. We’ll just have to wait and see what the medics say.”

Although Ruan Pienaar is first-choice scrum-half, as the World Cup-winning South African’s understudy, Marshall is a vital member of the Ulster squad. He has made 76 appearances for the province, 25 of them this season.

Like Stephen Ferris before him ahead of the quarter-final defeat of Munster, Marshall will be given every chance to recover and prove his fitness.

Reigning European champions Leinster are coming to Ravenhill on Friday night for a possible Heineken Cup Final dress-rehearsal, but McLaughlin insists his eyes are focused on the Pro12 clash rather than anything beyond it.

“After Saturday’s result, we need a win if we are to be in with a chance of making the Pro12 play-offs,” he said.

With Afoa ruled out, McLaughlin’s big call on Friday night will be at number three. Tom Court played there on Saturday, Adam Macklin got a run off the bench and Declan Fitzpatrick, sidelined by a neck injury since November, is in contention for a comeback.